I imagine GIMP would shrink digital camera pictures, but I couldn't figure out how immediately and it seemed like overkill.

My digital pictures are 5-30 MB each and I would just like a quick and easy way to shrink them down to 100 KB or less each for emails? Which Linux software does this easy enough that you wouldn't have to explain to me how to do it?

You could zip them or use gz or bz but the best would be to convert them to jpg - you will loose some quality without doubt but the compression will be higherThe Gimp is really simple to learn - just open the photo > Save as and select quality and file type

If you're looking a tool like in Photoshop that you have a slider of quality and other settings and live it shows the final file size, in Gimp there's something similar. As carltonh says, click in Save as... enter a name with .jpg extension, click on 'Export' and a new dialog appears. Then, click on 'Show preview in window image' (maybe not accurate I'm using GIMP in Spanish) and a new window image pops-up and it shows you the file size. To get the lesser of the file size, click con 'Optimze', 'Progressive', 'Subsampling, the one it shows the lesser file size', and 'DCT Method Floating point'. And then move the slider in order to achieve the file size you want. Then click con 'Save defaults' and finally in 'Save'. From that moment, every time you want to save a jpeg image file, you'll have that settings, so it's just a 3 or 4 click process to each image.

But if you're looking for a specific application to do so: I don't know. I would do it with a different approach. First I would resize all the images to a slower definition on gThumb, which has a mass resize tool which works great. Then, I will open one by one in GIMP and do what I've wrote you up.

If you've minimun experience with the terminal, or if you're not afraid of it, may you try ImageMagick, which is a program to manage image in terminal. I think it should be something like resize -x 800 -y 600 -o jpg ./*, I don't know. Serch a little, because it's commonly used.

google picassa, has a feature to export entire websites, in this feature wizzard, you can set it to make a gallery style webpage, and it will resize and label your photos approparatly, and you still don't modify the originals. Also, it has some pretty advanced auto color and such tools, that are easier to operate than gimp.

For me, I'd just use a photoschop macro, cause then I get to use my own watermark.

The very best way to do it quickly is Phatchit has some awesome options to add watermarks, to round corners, add copywrites, and much more.once you set up how you want the picture to be, and where you want it to go, it is as simple as dragging a picture into its box and there you go!you can even put whole sets of photos in the box and it'll make em all the same.